Drawing equipment for a knitting machine

ABSTRACT

Drawing equipment for a knitting machine for the production of a fiber material from a roving includes double belts, guided via a pair of belt rollers and a pair of output pressure rollers. The pair of belt rollers and the pair of output pressure rollers respectively have an upper roller and a lower roller, which is driven by an electric motor. All of the drawing equipment rollers are disposed on the front-side of a base plate. Axles of the rollers are guided through the base plate. Drive means for the lower rollers of any roller pair are disposed at least partially on the rear-side of the base plate. Disposed on the upper roller of the pair of output pressure rollers and on the upper roller of the pair of belt rollers is suction equipment which extends over both of the upper rollers.

The invention relates to drawing equipment for a knitting machine for the production of a fibre material from a roving, having double belts, guided via belt rollers, and a pair of output pressure rollers, the belt rollers and the pair of output pressure rollers respectively having an upper pressure roller and a lower roller which is driven by an electric motor and the rollers being disposed on the front-side of a base plate, whilst the axles thereof are guided through the base plate and the drive means for the lower rollers are disposed at least partially on the rear-side of the base plate.

Such drawing equipment is already known from WO 2010/028513 A1. It serves for the purpose of producing a drawn fibre material from a roving and for supplying this directly to the needles of the knitting machine. In the case of these combined spinning-knitting machines, the production of a conventional, twisted yarn is therefore dispensed with. The knitted pieces produced from the drawn fibre material with essentially parallel-orientated fibres have in addition a softer surface than knitted pieces produced from a twisted yarn.

The drawing equipment of these spinning-knitting machines is subjected, like the drawing equipment of spinning machines, to fibre fly which can lead to contamination and operational disturbances. In particular, fibres or abraded material can accumulate in the gap between the rollers mounted to float on the base plate and the base plate and can lead to disturbances in operation of the drawing equipment. In the case of the known drawing equipment, the rear-side of the base plate is hence sealed in an air-impermeable manner with a housing and compressed air is introduced there, which compressed air is conducted through borings in the base plate towards the gap between the lower rollers and the front-side of the base plate. The compressed air is hence able to blow out the fibres situated in the gap an that these cannot become attached. The blown-away fibres can however subsequently become attached to other machine parts.

EP 0 532 457 A1 describes drawing equipment for spinning machines in which the pair of rollers are mounted to float on a closed drive housing. The drawing equipment rollers are covered by a housing which is open on the supply side of the roving. Compressed air is introduced into the drive housing and can flow through openings, provided for the mounting of the roller shafts in the drive housing, towards the drawing equipment rollers in the open housing. Outside the open housing, suction equipment which is connected to the open housing via a hose connection is disposed. This suction equipment is however greatly restricted in the effect thereof since the hose connection opens into the open housing at a position at a far remove from the drawing equipment rollers. In addition, the construction of this drawing equipment is very large so that this drawing equipment cannot be used in the case of spinning-knitting machines.

The object of the present invention resides in providing drawing equipment for spinning-knitting machines, which extensively avoids problems which occur due to fibre fly and abraded material.

The object is achieved by drawing equipment for a knitting machine for the production of a fibre material from a roving, having double belts, guided via a pair of belt rollers, and a pair of output pressure rollers, the pair of belt rollers and the pair of output pressure rollers respectively having an upper pressure roller and a lower roller which is driven by an electric motor, and the rollers being disposed on the front-side of a base plate, whilst the axles thereof are guided through the base plate and the drive means for the lower rollers are disposed at least partially on the rear-side of the base plate, characterised in that, on the upper roller of the pair of output pressure rollers and on the upper roller of the pair of belt rollers, suction equipment is disposed which extends over both upper rollers. In addition, a pair of input pressure rollers can be provided.

The drawing equipment according to the invention dispenses with a housing which at least partially covers the drawing equipment rollers and, instead, uses suction equipment specifically close to the production place of the fibre fly, in the region of the upper rollers which are situated nearest to the drawing equipment output. The suction equipment thereby extends over both rollers. One of the upper rollers is a belt roller. Hence the suction equipment serves also for cleaning the belts. Even dust penetrating from outside can be removed reliably from the drawing equipment with the suction equipment. By dispensing with the housing covering of the drawing equipment rollers, these are also always freely accessible for maintenance operations and for checking the drawing of the fibre material. The required installation space for the drawing equipment is small so that this can be used without difficulty for spinning-knitting machines.

The mode of operation of the suction equipment can be further optimised by the suction equipment at least covering the output upper roller at least partially at the free end thereof. The suction is consequently concentrated even more strongly on the rollers. In addition, the partial lateral covering of the upper roller prevents escape of loose fibres and fluff to the side.

Also in the case of the drawing equipment according to the invention, the rear-side of the base plate can be covered at least partially in an air-impermeable manner by a housing cover which is provided with at least one supply opening for compressed air, and the base plate can have through-openings for the compressed air. Hence air can be conducted from the drawing equipment rear-side and through the openings in the base plate to the drawing equipment rollers and there can reliably prevent attachment of abraded material, fluff or dust in cooperation with the suction equipment.

It is thereby of particular advantage if the through-openings in the base plate are formed by axial holes for the axles of the upper rollers, through which the upper roller axles are guided with clearance. In this way, the compressed air passes directly into the narrow gap between the roller bodies of the upper rollers and the base plate and, from the top, also into the corresponding gap between the lower roller bodies and the base plate and can therefore keep these gaps reliably free of accumulations of fibres or dust.

After the pair of output rollers, at least one nozzle for receiving the drawn fibre material can be disposed, with which a twist can be imparted to the fibre material. In this embodiment of the drawing equipment, it is advantageous if the suction equipment suctions off the fibre material upon blockage of the at least one nozzle. The fibre material cannot consequently become jammed in the drawing equipment and lead to contamination or even damage to the drawing equipment.

Furthermore, it is possible also to cover the front-side of the base plate at least in regions with a housing cover. This is in particular of advantage when the drive motors for the lower rollers are likewise situated on the front-side of the base plate and are covered by the housing cover and hence are protected from contamination.

In the following, a preferred embodiment of drawing equipment according to the invention is described in more detail with reference to the drawing.

There are shown in detail:

FIG. 1 a view of the front-side of the drawing equipment;

FIG. 2 an enlarged detailed view of the drawing equipment of FIG. 1;

FIG. 3 a sectional representation of the drawing equipment rollers and of the suction equipment of the drawing equipment of FIG. 1;

FIG. 4 a perspective view of the drawing equipment of FIG. 1;

FIG. 5 a detailed illustration of the lower rollers and of the upper roller axles of the drawing equipment of FIG. 1;

FIG. 6 an enlarged detailed illustration of an upper roller axle of FIG. 5.

The drawing equipment 10 of FIG. 1 has a base plate 11, on the front-side 11.1 of which a pair of input pressure rollers 12, 13, a pair of belt rollers 14, 15 and also a pair of output rollers 16, 17 are disposed to float. Between the pairs of rollers 12, 13, 14, 15 and 16, 17, in the case of which respectively the lower roller is driven by a motor, a roving, not shown here in more detail, is drawn to form a fibre material on the basis of the different speeds of the pairs of rollers 12, 13, 14, 15, 16, 17. At the output of the pair of output rollers 16, 17, a nozzle 18 which has a transport pipe 19 is disposed, which output rollers conduct the fibre material to a knitting machine, preferably a circular knitting machine, which is likewise not shown here. Furthermore, suction equipment 20 is disposed on the front-side 11.1 of the base plate 11 and extends over the upper rollers 17 and 15 of the pair of output rollers 16, 17 and of the pair of output-side belt rollers 14, 15. It is hence able to suction off fluff, dust and abraded material, which are produced when drawing the roving, at the production place so that these particles cannot be deposited at a different place in the drawing equipment.

It can be detected in particular from the enlarged detailed view in FIG. 2 that the suction equipment 20 overlaps the output upper roller 17 also at the side so that even laterally emerging fibres or fluff can be reliably caught.

It is evident from the sectional image in FIG. 3 that the suction equipment 20 is in addition disposed such that, upon blockage of the nozzle 18, the produced fibre strand can be reliably suctioned off by the suction equipment 20. A lower part 20.1 of the suction equipment 20 abuts directly on the nozzle 18 for this purpose.

FIG. 4 shows the rear-side of the base plate 11 which is covered completely by a housing cover 21. In the housing cover 21, a supply opening 22 for compressed air is disposed.

As FIGS. 5 and 6 clarify, this compressed air flows from the rear-side of the base plate 11 to the front-side 11.1 thereof through through-openings 23, 24 and 25 for axles 26, 27, 28 for the upper rollers 13, 15, 17 (see FIG. 1).

FIG. 6 clarifies, in the enlarged illustration, the circular through-opening 23 for the axle 26 of the output upper roller 17. Like the other axles 24 and 25, the axle 26 is also guided through the associated through-opening 23 with clearance in order that the upper rollers 13, 15, 17 can be subjected to a clamping device, not illustrated here in more detail, and can be moved against the lower rollers 12, 14, 16. 

1. Drawing equipment for a knitting machine for the production of a fiber material from a roving, comprising: double belts; a pair of belt rollers; and a pair of output pressure rollers; wherein the double belts are guided by the pair of belt rollers and the pair of output pressure rollers; wherein the pair of belt rollers and the pair of output pressure rollers respectively have an upper roller and a lower roller, which is driven by an electric motor; wherein all of the rollers are disposed on a front-side of a base plate, whilst axles thereof are guided through the base plate; wherein drive means for the lower rollers are disposed at least partially on a rear-side of the base plate; and wherein on the upper roller of the pair of output pressure rollers and on the upper roller of the pair of belt rollers, suction equipment is disposed which extends over both of the upper rollers.
 2. The drawing equipment according to claim 1, further comprising a pair of input pressure rollers.
 3. The drawing equipment according to claim 1, wherein the suction equipment at least covers the upper output roller of the pair of output pressure rollers at least partially at a free end thereof.
 4. The drawing equipment according to claim 1, wherein a rear-side of the base plate is covered at least partially in an air-impermeable manner by a housing cover provided with at least one supply opening for compressed air, and wherein the base plate has through-openings for the compressed air.
 5. The drawing equipment according to claim 4, wherein the through-openings are formed by axial holes for the axles of the upper rollers, through which upper roller axles of the roller pairs are guided with clearance.
 6. The drawing equipment according to claim 1, further comprising at least one nozzle for receiving the drawn fiber material is disposed after the pair of output rollers.
 7. The drawing equipment according to claim 6, wherein the suction equipment suctions off the fiber material upon blockage of the at least one nozzle.
 8. The drawing equipment according to claim 1, wherein a front-side of the base plate is covered at least in regions with a housing cover. 